1. Field of the Invention
The present invention relates to a liquid crystal display device (LCD), and more particularly, to a multi-domain liquid crystal display device having a dielectric frame in or around divided pixel region, and having a special dielectric frame on the center of the divided pixel region.
2. Description of the Related Art
Recently, a LCD has been proposed where the liquid crystal is not aligned, and the liquid crystal is driven by side electrodes insulated from pixel electrodes. FIG. 1 is a sectional view of pixel unit of the conventional LCDs.
Regarding conventional LCDS, first and second substrates, a plurality of gate bus lines arranged in a first direction on a first substrate and a plurality of data bus lines arranged in a second direction on the first substrate divide the first substrate into a plurality of pixel regions.
The TFT is formed on each pixel region on the first substrate and comprises a gate electrode, a gate insulator, a semiconductor layer, a ohmic contact layer, a source electrode, a drain electrode, etc.
The passivation layer 37 is preferably formed over the whole first substrate.
The pixel electrode 13 is coupled to the drain electrode on the passivation layer 37.
Side electrode 21 is overlapped with a part of pixel electrode 13 on the gate insulator.
On the second substrate, a light shielding layer 25 is formed shielding light leakage from the gate bus line, data bus line, and TFT. A color filter layer 23 is on light shielding layer 25. A common electrode 17 is on color filter, layer 23. And a liquid crystal layer is between the first and second substrates.
The side electrode 21 formed around the pixel electrode 13 and an open area 27 of the common electrode 17 distort the electric field applied to the liquid crystal layer. Then, in a unit pixel, liquid crystal molecules are variously driven. This means that when voltage is applied to the LCD, dielectric energy due to the distorted electric field arranges the liquid crystal directors in a needed or desired position.
However, to obtain a multi-domain effect, open area 27 in common electrode 17 is necessary, which requires patterning of the common electrode 17. Moreover, if the electrodes do not have an open area or the open area is narrow, the distortion of electric field needed to divide the pixel region becomes weak. Then, the time needed the liquid crystal directors to become stable increases. Further, according to the division of the domain due to the open area 27, the liquid crystal texture has an irregular structure. As a result, the quality of display is deteriorated. Also, the brightness and the response time increase because a strong electric field is formed between the pixel electrode 13 and the side electrode 21.